What happens when a jet ski sucks up rocks? Any mechanics help me out ? please?

Question

How bad does it damage it?

Answer 1

Could do nothing, could completely ruin you drive.. it all depends. Most likely you will damaga your impellor.. I think thats how its spelled. You have what is almost like a fan that sucks up the water and then pushes it out the back. Theres more to it than that but thats the basic idea of it. Throw a rock into a fan and see what happes.. thats what will happen to your jet ski.

Answer 2

There is a set of grates on the intake of the jet pump on all jet skis.  The size of the rock sucked up will be limited depending on the space between the grates   Usually  only small gravel could be sucked  into the pump.  Larger rocks will be filtered and kept out.    Most of the time, only the impeller gets dinged up or bent  &  sometimes the blades get broken off.  It must be replaced and the shaft should be checked to see if it is bent.  If so, it must be replaced also.

Answer 3

All good answers so far.  However, small stones and pebbles can get into the cooling supply hose.  If they jam in there, it can spell real trouble.  Watch your temp gage and make sure it's not overheating.  I have rebuilt many machines, and usually clean half a handful of stones out of the engine's cooling jackets.  No problem unless they clog a hose.  Avoid running in less than 2-3 feet of water, and only idle it.  The newer machines with >200 HP can suck rocks up from 5 feet down - I've seen it.